I have the Edelbrock ProFlow XT EFI, and the T-stat flange has the standard SBF T-stat bypass hole, and Edelbrock says that it is indeed necessary to install the pump to manifold hose, but unlike the stock EFI which has plumbing into the throttle body area and a tap for the heater supply, Edelbrock has only internal flow (makes sense, colder air, more dense, etc). They have their water temp sensor for the ECU in one tapped port on drivers side front, and there is another plugged port in a flow path on the opposite side front plus a third one back in the back drivers side that dead heads at the manifold - a water port in the back of the head, blocked by the manifold. A stock T-stat housing also has a tapped port on the top that is generally plugged, but is a great place for a flow path signal.

I will have three sensors to install (ECU, Fan Controller, Dash Gauge), plus flow to the heater to deal with. I was first thinking of using a "T" coming off the water pump with one leg into the intake and the second to the heater, then using the three tapped ports for my sensors but I'm not sure about the dead headed port in the back giving accurate temps. Now I am strongly leaning to using a stock T-stat housing and Ford elbow from pump to intake, putting my sending units up front - two in the manifold ports, one in the T-stat housing, and tapping my heater hose off of the dead headed port in the back. This would eliminate a heater hose up front in a very congested area.

With all of this background, am I going to get the necessary flow for the heater from the deadheaded port in the back of the manifold? Also, is that port dead headed for a reason? It wil only see flow when the heater is in service, and I really like the idea of getting one hose away from the RF of the engine.